Catadioptric imaging system

Claim 1

A catadioptric imaging system, especially suited for use in broad-band ultraviolet applications, comprising: an aberration corrector means disposed at the entrance end of said system and including a plurality of lens elements, all formed from a single refractive material type, for providing high levels of correction for aberrations and chromatic variation of aberrations of light within said system; a first focusing lens element, formed from said refractive material type and disposed at a first predetermined position along an optical path of said system, for focusing light received from said corrector means at an intermediate image point along said path; a second lens element, formed from said refractive material type and disposed at a second predetermined position along said optical path subsequent to said first focusing lens element and said intermediate image point, said second lens element being operative to act in conjunction with said first focusing lens element to correct primary longitudinal color of light within said system; a third field lens element, formed from said refractive material type and disposed at a third predetermined position along said optical path between said first and second lens elements, for correcting secondary longitudinal color of light passing through said system, and further disposed relative to said intermediate image point such that tertiary longitudinal color is also corrected within said system; a planar mirror element, disposed along said path at the exit end of said system and having a small exit aperture formed therein, for reflecting light transmitted thereto through said second lens element; and, a spherical mirror element, disposed at a fourth predetermined position along said path between said third position and said second position, and having a centrally disposed hole therein, whereby light transmitted by said third lens element passes through said hole, then a first time through said second lens element to said planar mirror element, whereupon it is reflected back a second time through said second lens element to said spherical mirror element and subsequently reflected thereby through said second lens element a third time and through said exit aperture whereby a focused image is produced at a final image point.

Claim 15

A method for imaging a broad spectral range of light at fast speed, using only one refractive material, comprising the steps of: positioning a first focusing lens element, formed from said single refractive material type, at a first predetermined position within an optical system, whereby incident light is focused thereby at a predetermined intermediate image point within said system; positioning a second lens element, formed from said refractive material type, at a second predetermined position within said system subsequent to said first focusing lens element and said intermediate image point, said second lens element being operative to act in conjunction with said first lens element to correct primary longitudinal color of light within said system; positioning a third field lens element, formed from said refractive material, at a third predetermined position within said system between said first and second lens elements, said third field lens element being operative to act in conjunction with said first and second lens elements to correct light within said system for secondary longitudinal color; positioning a planar mirror element, having a small exit aperture formed therethrough, at the exit end of said system for reflecting light transmitted thereto through said second lens element; positioning a spherical mirror element, having a centrally disposed hole therethrough, between said second and third lens elements whereby said light transmitted through said third lens element passes through said hole in said spherical mirror element, then through said second field lens element, and is subsequently reflected by said planar mirror element to the concave reflective surface of said spherical mirror element, whereby said light is subsequently reflectively focused through said first hole in said planar mirror element and to said final image point.

Claim 16

A method for imaging a broad spectral range of light at fast speed, using only one refractive material, comprising the steps of: positioning a first focusing lens element, formed from said single refractive material type, at a first predetermined position within an optical system, whereby incident light is focused thereby at a predetermined intermediate image point within said system; positioning a second lens element, formed from said refractive material type, at a second predetermined position within said system subsequent to said first focusing lens element and said intermediate image point, said second lens element being operative to act in conjunction with said first lens element to correct primary longitudinal color of light within said system; positioning a third field lens element, formed from said refractive material, at a third predetermined position within said system between said first and second lens elements, said third field lens element being operative to act in conjunction with said first and second lens elements to correct light within said system for secondary longitudinal color; positioning a planar mirror element, having a small exit aperture formed therethrough, at the exit end of said system for reflecting light transmitted thereto through said second lens element; positioning a spherical mirror element, having a centrally disposed hole therethrough, between said second and third lens elements whereby said light transmitted through said third lens element passes through said hole in said spherical mirror element, then through said second field lens element, and is subsequently reflected by said planar mirror element to the concave reflective surface of said spherical mirror element, whereby said light is subsequently reflectively focused through said first hole in said planar mirror element and to said final image point.